If r = 12 cm, m = 310 g, and m = 40 g , find the speed of the block after it has descended 50 cm starting from rest. solve the problem using energy conservation principles. (treat the pulley as a uniform disk.)

Explanation:

While mass is falling downwards there is no frictional loss so here we can use mechanical energy conservation

So change in gravitational potential energy = gain in kinetic energy of the system

for uniform cylinder we will have

now we have

now we have